Theory and classification of mass extinction causationOA

Theory regarding the causation of mass extinctions is in need of systematization, which is the focus of this contribution. Every mass extinction has both an ultimate cause, i.e. the trigger that leads to various climato-environmental changes, and one or more proximate cause(s), i.e. the specific climato-environmental changes that result in elevated biotic mortality. With regard to ultimate causes, strong cases can be made that bolide(i.e. meteor) impacts, large igneous province(LIP) eruptions an...     

Global weirding at mass extinction horizonsOA

<正>A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].     

Mass extinctions,their causes and consequences: an interview with Douglas H.Erwin and Shuzhong ShenOA

<正>‘Mass extinctions’ have been a hot topic for several decades. What triggers a mass extinction? How does a mass extinction impact the evolution of life? How does our ecosystem recover after a mass extinction? These questions attracted the interest of both scientists and the public alike.NSR spoke to two renowned researchers in the field of mass extinctions: Prof. Douglas H. Erwin from the National Museum of Natural History of the USA, and Prof. Shuzhong Shen from Nanjing University, Chin...     

The Lopingian Series of China and End-Permian Mass Extinction

The end-Permian mass extinction is the greatest bioevent in the geological history, which wiped out nearly 95％ of the marine species and 75％ of the terrestrial species,followed by a biological winter for more than five million years.The cause and the process of the end-Permian mass extinction remain an unsolved mystery in earth science and one of the most difficult and interesting scientific problems.     

A common variant in AAK1 reduces risk of noise-induced hearing lossOA

<正>Noise-induced hearing loss (NIHL) is one of the most common types of hearing loss and contributes to significant morbidity worldwide,as well as being the major cause of age-related hearing loss and tinnitus.The World Health Organization (WHO) estimates that 10%of the world’s population is exposed to sound levels that could potentially cause NIHL[1].It has been widely accepted that NIHL is a multifactorial genetic disorder with estimated heritability of 36%to 40%[2].Ideally,identificatio...     

The great catastrophe: causes of the Permo-Triassic marine mass extinctionOA

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the cr...     

An action plan for the agri-food sector at the time of the climate and biodiversity crisesOA

<正>Land areas on our planet are facing unprecedented levels of stress.More than70%of the global ice-free land has been affected by human activities,30%of the land is threatened by degradation,biodiversity and other ecosystem services(ESs) are declining,and climate change is altering ecosystem functioning [1].Currently,agriculture is the dominant form of land use,with grazing land comprising27%and cropland 12%(and more than half of the cropland is used to produce animal feed).Agriculture is...     

Exploring the real causes of the end-Permian mass extinction

<正>Of the‘big ive’mass extinction events in the Earth’s history[1],the end-Permian extinction was the largest.Over the past30 years,the end-Permian extinction hasatracted a lot of atention with many causes being suggested for the mass extinction.Suggestions have included asteroid impact,Siberia volcanism eruption,     

Challenges and opportunities for modeling coupled human and natural systemsOA

<正>The Earth is a very large and complex system that consists of human and natural components interacting bidirectionally with each other,thus forming coupled human and natural systems (CHANS)[1].The increasing dominance of human impacts,especially after the 1950s [2],marked a new era for the Earth,the Anthropocene,which means humans have become the main drivers of the evolution of changes in the Earth system.Therefore,modeling CHANS is essential for understanding the emergent system prope...     

Revisiting non-linear Thomson scattering with metamaterialsOA

<正>Non-linear optics is a branch of optics that studies the intriguing and sometimes unexpected ways in which light and matter interact at high intensities, when the polarization density does not respond linearly to the electric field of the light. The pursuit of the perfect non-linear optical material has been ongoing ever since the pioneering experiment on second harmonic generation carried out by Franken in 1961 [1]. Indeed,     

Late Ordovician Mass Extinction: Earth,fire and iceOA

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and intr...     

Windows of opportunity:a new tree-shrub dynamic at alpine treeline?

<正>Of increasing importance while the climate is under the influence of chronic environmental change driven by rising levels of CO₂,temperature and vapor pressure deficit(VPD),is understanding how vegetation will respond over space and time as we cross critical thresholds [1].This is especially true in mountain regions where amplified rates of warming are expected to affect the elevational zonation of plant communities [2].     

China's space robotics for on-orbit servicing: the state of the artOA

<正>Since the pioneering deployment of Canadarm in 1981,various on-orbit servicing (OOS) concepts have been flourishing and are continuously demonstrated by space agencies worldwide[1].This novel access to extend human curiosity in space is empowered by the remarkable OOS progress achieved by missions like the Robot Technology Experiment (ROTEX),Engineering Test Satellite-Ⅶ(ETS-Ⅶ),     

Microbes in mass extinction: an accomplice or a savior?OA

<正>Microbes include various types of organisms that are invisible to the naked eye,e.g. bacteria, archaea and microeukaryotes. Although the precise number remains largely unknown, microbes are recognized as the unseen majority of our biosphere [1]. As a group of organisms classified by body size, microbes cover a considerable spectrum of metabolisms,     

Paleomagnetic,tectonic and geochronological constraints for Permian-Triassic oroclinal bending of the Mongolian collage

<正>The Central Asian Orogenic Belt constitutes the Kazakhstan and Mongolian oroclinal collages located between the Tarim-North China collage(TNC)to the south and the Siberian craton to the north(Fig.1a) [1].While the oroclinal bending of the western Kazakhstan collage is widely accepted by the paleomagnetic and tectonic community,the oroclinal bending model of the eastern Mongolian collage is disputed[2,3].Despite differences,     

Confirming of the Higgs Boson

<正>1.Significance of the search for the Higgs boson General relativity and the Standard Model are two major theories in modern physics.General relativity describes space,time and gravity,while the Standard Model is a theory concerning the electromagnetic,weak,and strong nuclear interactions.The Standard Model divides particles into the two categories of fermions(including quarks and leptons)and bosons(including gluons,photons,W and Z bosons and the Higgs boson)according to their spin.According to the Standard Model’s predictions,there are a total of 61 particles in these two categories[1].All the particles but the Higgs boson have been experimentally supported and validated.The Higgs particle is a boson with no spin or electric charge,it has mass     

Two distinct Paleozoic metamorphic events in the Tarim-North China Collage

<正>The Central Asian Or ogenic Belt(CAOB) [1],which includes the Altaids in Central and Northern Asia [2],is the largest accretionary orogen formed during the subduction of the Paleo-Asian Ocean and the Panthalassa Ocean in the period of the Late Proterozoic to Late Paleozoic [3].Closure of the Paleo-Asian Ocean is attributed to the northward drift of the North China and Tarim cratons leading to the massive shortening and oroclinal buckling of the CAOB accretionary system in the Permian [4...     

Evolution of artificial ion channelsOA

<正>Protein ion channels on a cell membrane generate action potentials for cellular signal transduction, and regulate biological activities during life. Since the discovery of the asymmetric ion transport phenomenon in quartz nanopipettes by Bard and colleagues [1], synthetic nanofluidic materials and devices have attracted a lot of research interests from the scientific community,     

Efficient and Clean Utilization of Waste-generated Energy Gives Birth to an Emerging “Urban-mining” Industry

<正>1.Scientific connotation and significance The large amount of wastes on the earth makes a gigantic energy and resource bank,which can be used both directly for generating new energy and for saving resources through recycling and regeneration.Generally speaking,the efficient and clean utilization of wastegenerated energy refers to the recycling of a great amount of valuable substances from the solid materials that have quitted the production link or consumption field via certain technical,economical means and management measures,to achieve biosafety disposal,pollutant emission reduction and the comprehensive utilization of wastes for both economic and public welfare[1].At present,the effi cient and clean utilization of waste-generated energy is mainly implemented through the use of renewable energy,     

Solar Photovoltaic Grid Parity Will Come True

<正>1.Current situation and challenges of solar photovoltaic Solar photovoltaic(PV)is the most promising direction with the fastest growth among solar power technologies.The PV installed capacity has enjoyed an annual growth rate of 60%since 2008,and by 2012,the global accumulative installed capacity exceeded 100 GW for the fi rst time[1].It is predicted by the International Energy Agency that PV will generate about 11%of the world’s electricity by 2050,reducing CO2 emission by approximately 2.3 billion tons annually[2].However,solar PV also faces significant challenges.Firstly,solar energy has low energy intensity and is susceptible to sunlight hours,radiation levels and other